Fluorescent lamp starter



1944- R. M. SMITH ETAL 2,355,476

, FLUORESCENT LAMP STARTER Fi led June 24, 1942 INVENTORS R. M SM/T/r J?.5? 6775 ATTORNEY Patented Aug. 8, 1944 UNITED STATES PATENT OFFICEFLUORESCENT LAMP STARTER Application June 24, 1942 Serial No. 448,240

8 Claims.

The present invention relates to gaseous discharge lamps andparticularly to a relay for the starting and operating of such lamps ofthe fluorescent type from the usual source of electrical energy of thecustomary domestic potential.

It is customary with lamps of this type to connect thefllamentaryelectrodes in series with an inductance element across the domesticsource of supply, and a relay device such as shown in Patent 2,200,443,issued May 14, 1940, to E. C. Dench, is employed to first connect thefilamentary electrodes in a series heating circuit to raise thetemperature thereof to electron emissivity, after which the relayoperates to interrupt the series heating circuit and causes a highvoltage surge from the series-connected inductance, which thus initiatesa discharge between the preheated electrodes.

The difiiculty with such circuit arrangement resides in the fact that ifthe discharge lamp becomes defective, such as by loss of theelectronemissive material from the electrodes, and the dischargeaccordingly fails to start for any reason, the relay continues tooperate indefinitely, thus not only shortening its useful life but sinceit repeatedly completes and interrupts the series heating circuit of thefilamentary lamp electrodes.

the latter will intermittently glow and constitutes a source ofannoyance to the user with attendant waste of electrical energy.

It is accordingly an object of the present invention to provide astarting and operating arrangement for a gaseous discharge lamp whereina relay unit is employed to initiate a discharge in the lamp whileconsuming an insignificant amount of energy during operation of thelatter, and which relay unit operates to prevent glowing oi' the lampelectrodes by locking out the lamp in the event a discharge is notinitiated therein after several operations of the relay.

Another object of the present invention is the provision of a relay unitfor starting and operating a gaseous discharge lamp which can be readilyinserted in the starter socket and is operable to initiate a dischargein the latter while consuming an insignificant amount, of energy oncesuch discharge is started; but in the event the lamp becomes detective,the relay operates to "lock out" the lamp and is automatically returnedto its normal position upon replacement of the defective lamp.

Still further objects of the present invention will become obvious tothose skilled in the art by reference to the accompanying drawingwherein: Fig. 1 is a sectional view in elevation of the relay unit ofthe present invention and showing the relative arrangement of thevarious parts:

geport, Conn, a corpo- Fig. 2 is a fragmentary sectional view or therelay unit of the present invention identical to Fig. 1 except that itshows the position of the various parts when the relay is in the lamplockout" position;

Fig. 3 is a sectional view taken on the line IIIIII of Fig. 1 andlooking in the direction indicated by the arrows, and

Fig, 4 is a schematic diagram of the starting and operating circuit fora discharge lamp and employing thenovel relay unit of the presentinvention.

Referring now to the drawing in detail, the relay unit 4 shown in Fig. 1comprises a casing 6 of a plastic material or light metal permanentlyclosed at one end and having its other end closed by an insulating cap 6provided with a pair of socket terminals I and I and held in place as bybent lugs 5 protruding from the casing 5. Disposed within this casing isa glow switch Ill of the type shown in Patent 2,228,210, issued January'7, 1941, to R. F. Hays, Jr., comprising a vitreous envelope providedwith an ionizable medium at a suitable pressure and having a pair ofelectrodes l2 and I3 (Fig. 4), one 01 which I2 is a bimetallic element.A radio frequency suppressing condenser I4 is also housed within thecasing 5 and is connected in shunt across the glow switch iii.

In addition, a thermal relay is supported withing the casing 5 by theinsulating cap 6. This thermal relay comprises a bimetallic element l5anchored at one end to the insulating cap as by projections i8 thereonpassing through apertures 3| gripping that portion of said captherebetween.

The element i5 is bent upon itself to form a corrugation, with its otherend carryin a contact l1 normally engaging a contact [8, the latter ofwhich is supported by an eyelet or the like lil passing through theinsulating cap 6. A low resistance heater element 20 is wound about thebimetallic element i5, but insulated therefrom by a sleeve of heatresistant material such as asbestos or the like 22, with one end of thislow resistance heater element being'connected directly to the socketcontact terminal 1, while its remaining end is connected directly to thebimetallic element I 5, as can be appreciated from Fig. 4.

The stationary contact terminal I8 is in turn connected to the electrodel3 of the glow switch by a conductor 23, while the bimetallic electrodell of the glow switch is connected to the remain ing socket contactterminal 8 by a conductor 24. A high resistance heater element 25 isdisposed beneath the corrugation formed in the bimetallic element withits ends connected respectively to the socket contact terminals 1 and I,which thus disposes the high resistance heater element normally in ashunt circuit with the glow switch l2, condenser H, bimetallic elementII together with the contacts IT and I8, as well as the low resistanceheater element 20.

Referring now more particularly to Fig. 4, a starting and operatingcircuit is shown for initiating a discharge in a discharge lamp andemploying the relay of the present invention as above described. Thedischarge lamp 2. is provided with filamentary electrodes 21 and 28. Asshown, one end of the filamentary electrode 21 is connected through aninductance element 29 to one side Li of a source of customary domesticpotential of l-230 volts. Likewise, one end of the filamentary electrode2! is connected through a switch 30 to the other terminal of the supplysource L2. The remaining ends of the filamentary lamp electrodes 21 and28 are connected together by the relay unit 4. Upon closure of theswitch 30, a series heating circuit for the filarnentary lamp electrodes21 and II is completed from the supply source LI through the inductanceelement 29, filamentary electrode 11, to the socket terminal 8, andthence through the glow switch l0, normally closed contacts I! and il,bimetallic element l5, low resistance heater element to the socketterminal I, and thence through filamentary electrode 20 and switch IIback to the other supply terminal L2.

Thus, substantially the full potential of the supply source LIL2 isimpressed across the electrodes l2 and I! of the glow switch II, whichvoltage is sufficient to initiate a glow discharge between theelectrodes l1 and II. This discharge accordingly heats the bimetallicelectrode i2, causing it to deflect into engagement with the electrode13, thus positively completing a series heating circuit to thefilamentary lamp electrodes 7 and 28, allowing them to be very rapidlyraised to an electron-emitting temperature.

By the time these latter electrodes have reached an electron-emittingtemperature, the bimetallic electrode I! of the glow switch I. will havecooled, disengaging the electrode ii and returning to its normalposition. Disengagement of the glow switch electrodes i2 and I! willcause a high voltage surge or kick from the inductance 29, which thusinitiates a discharge across the preheated lamp electrodes 21 and II. Iffor any reason a discharge is not initiated in the discharge lamp 26upon initial operation of the glow switch it, it will repeat itsoperation a number of times until such discharge is finally initiated.Once such discharge is initiated, only lamp voltage is impressed acrossthe electrodes l2 and I! of the glow switch H) which is insufficient toagain cause a glow discharge, with the result that the entire glow relayunit 4 consumes very little energy during operation of the lamp.

If the discharge lamp II has become defective, such as by thefilamentary lamp electrodes 21 and 28 having lost theirelectron-emissive coating, the glow switch i0 will continue itsrepetitious operation for a predetermined period of time. The continuedapplication of substantially the full potential of the source of supplyLl--L2 to the glow switch in for this predetermined period of time willcause the low resistance heater element 20 to gradually heat thebimetallic element I! through the asbestos insulation 21. when thebimetallic element 20 reaches the proper temperature, it deflects andopens the contacts ll and II, as shown in Fig. 2, which thus interruptsthe series heating circuit for the filamentary electrodes 21 and 2|, aswell as the circuit to the glow switch II and the low resistance heaterelement 20.

The high resistance heater element 25 which was formerly in a shuntcircuit with the glow switch II and low resistance heater II is nowimpressed with substantially the full potential of the source of supplyLI-LI, and while it draws negligible current, nevertheless sumcient heatis produced by this high ohmic resistance heater 25 to heat thebimetallic element ii and maintain the contacts I! and II in an openposition, thus "locking out" the defective lamp 2..

Interruption of the circuit to the glow switch It by maintaining thecontacts I! and II in an open position prevents continued operation ofthe glow switch II in a futile attempt to initiate a discharge in thedefective lamp 2.. However, upon replacement of the defective lamp, thecircuit is then broken to the high ohmic resistance heater element IIwhich thus allows the relay unit to return to its normal positionpreparatory to performing its cycle of operation to initiate a dischargein the lamp 2 in the manner above described.

It thus becomes obvious to those skilled in the art that a simple yetefficient circuit arrangement is provided by the present inventionwherein a relay unit is employed for the starting and operating of adischarge lamp, particularly of the fluorescent type. Moreover, when thelamp becomes defective and will accordingly not start after apredetermined period of time following initial operation or the relayunit, the latter automaticallv operates to "lock out" the defectivelamp, which thus in effect disconnects the latter from the source ofsupply, thereby preserving the useful life of the relay unit and at thesame time eliminating annoyance of continued glowing of the filamentarylamp electrodes. Furthermore, the amount of energy consumed by the relaywhile in its lock-out" position is negligible regardless of the timesuch relay remains in its locked-out" position until the defective lampis replaced.

Although one specific embodiment of the present invention has been shownand described, it should be understood that other modifications thereofmay be made without departing from the spirit and scope of the appendedclaims.

We claim:

1. In combination, a gaseous electric discharge lamp containing athermionic cathode and a cooperating electrode, and a starting andoperating circuit therefor comprising an inductance. means connectingone end of said thermionic cathode and said cooperating electrode acrossthe terminals of a current source in series with said inductance, and arelay device connected across the opposite end of said thermioniccathode and to said electrode for initiating a discharge in said lampand for locking out said lamp in the event the same becomes defectivecomprising a glow discharge device operable to initiate a discharge insaid lamp, a relay including actuating means included in series withsaid glow discharge device and a pair of normally closed contacts forcompleting a circuit to said actuating means and to said glow dischargedevice and operable by said actuating means only upon continuedoperation of said glow discharge device for a predetermined period oftime to cause opening of said contacts, means normally connected in ashunt circuit with said glow discharge device and said actuating meansand operable upon opening of said contacts to maintain said contacts inan open position and interrupt the circuit to said glow discharge devicewhen said discharge lamp becomes defective, and said last mentionedmeans being automatically operable to cause closure oi said contacts andrestoration of said relay device for normal operation upon replacementof the detective lamp.

2. In combination, a gaseous electric discharge lamp containing athermionic cathode and a cooperating electrode, and a starting andoperating circuit therefor comprising an inductance, means connectingone end of said thermionic cathode and said cooperating electrode acrossthe terminals of a current source in series with said inductance, and arelay device connected across the opposite end of said thermioniccathode and to said electrode for initiating a discharge in said lampand for locking-out said lamp in the event the same becomes defectivecomprising a glow discharge device operable to initiate a discharge insaid lamp, a relay including actuating means included in series withsaid glow discharge device and a pair of normally closed contacts forcompleting a circuit to said actuating means and to said glow dischargedevice and operable by said actuating means only upon continuedoperation of said glow discharge device for a predetermined period oftime to cause opening of said contacts, a high resistance heater elementnormally connected in a shunt circuit with said glow discharge deviceand said actuating means and operable upon opening of said pair ofcontacts to maintain said contacts in an open position and to interruptthe circuit to said glow discharge device to prevent operation of thesame in a futile attempt to start said discharge lamp when the latterbecomes detective, and said high resistance heater being automaticallyoperable to cause closure of said contacts and restoration of said relaydevice for normal operation upon replacement oi the detective lamp.

3. In combination, a gaseous electric discharge lamp containing athermionic cathode and a cooperating electrode, and a starting andoperating circuit therefor comprising an inductance, means connectingone end of said thermionic cathode and said cooperating electrode acrossthe terminals of a current source in series with said inductance, and arelay device connected across-the opposite end of said thermioniccathode and to said electrode for initiating a discharge in said lampand for locking-out said lamp in the event the same becomes defectivecomprising a glow discharge device operable to initiate a discharge insaid lamp, a relay including a bimetallic element and a resistanceheater therefor together with a pair 01 normally closed contacts forcompleting a circuit to said resistance heater and to said glowdischarge device and operable by said resistance heater only uponcontinued operation of said glow discharge device for a predeterminedperiod of time to cause opening oi. said contacts, a high resistanceheater element normally connected in a shunt circuit with said glowdischarge device and said actuating means and operable upon opening ofsaid pair of contacts to heat said bimetallic element and maintain saidcontacts in an open position to interrupt the circuit to said glowdischarge device to prevent operation of the same in a futile attempt tostart said discharge lamp when the latter becomes defective, and saidhigh resistance heater being automatically rendered mal operation uponreplacement of the defective lamp.

4. In combination, a gaseous electric discharge lamp containing athermionic cathode and a cooperating electrode, and a starting andoperating circuit therefor comprising an inductance, means connectingone end of said thermionic cathode and said cooperating electrode acrossthe terminals of a current source in series with said inductance, and arelay device connected across the opposite end of said thermioniccathode and to said electrode for initiating a discharg in said lamp andfor locking-out said lamp in the event the same becomes defectivecomprising a glow discharge operable to initiate a discharge in saidlamp, a thermal relay including a low resistance heater element inseries with said glow discharge device and a pair of normally closedcontacts and operable only upon continued operation of said glowdischarge device for a predetermined period of time to heat said thermalrelay and cause opening of said contacts with interruption oi thecircuit to said glow discharge device, a high ohmic resistance heaternormally connected in a shunt circuit with said glow discharge deviceand said low resistance heater and operable upon opening of saidcontacts to heat said thermal relay and maintain said contacts in anopen position to interrupt the circuit to said glow discharge device toprevent operation of the same in a futile attempt to start saiddischarge lamp when the latter becomes defectiv and said high resistanceheater being automatically rendered inoperative with attendant closureof said contacts and restoration of said relay device for normaloperation upon replacement of the detective lamp.

5. In combination, a gaseous electric discharge lamp containing athermionic cathode and a cooperating electrode, and a starting andoperating circuit therefor comprising an inductance, means connectingone end of said thermionic cathode and said cooperating electrode acrossthe terminals of a current source in series with said inductance, and arelay device connected across the opposite end of said thermioniccathode and to said electrode for causing the initiation of a dischargein said lamp and for locking-out said lamp in the event the same becomesdefective comprising a glow switch provided with electrodes one 01'which is a bimetallic element adapted to be heated by the ensuing glowdischarge upon the application of the voltage of said current sourcetherebetween, said bimetallic electrode being operable to deflect intoengagement with the other electrode of said glow switch to complete aseries heating circuit for said thermionic cathode and to extinguishsaid glow discharge and operable upon cooling thereof to interrupt saidseries heating circuit and cause a high voltage surge from saidinductance across the electrodes of said lamp with attendant initiationof a discharge therebetween, and a thermal relay comprising aheat-responsive member normally closing a pair of contacts and aresistance heater ele-' said glow switch and first mentioned resistanceheater and operable upon opening of said contacts to heat saidheat-responsive member and maintain said contacts in an open position tointerrupt the circuit to said glow switch to prevent operation of thesame in a futile attempt to start said discharge lamp when the latterbecomes defective and said high resistance heater being automaticallyrendered inoperative with attendant closure of said contacts andrestoration of said relay device for normal operation upon replacementof the defective lamp.

6. A relay unit for starting and operating a discharge lamp comprising acasing, a glow switch disposed in said casing provided with electrodestherein one of which is a bimetallic element and between which a glowdischarg occurs upon the application of the potential of the source ofsupply for the discharge lamp, said bimetallic electrode being operableto deflect into engagement with the other electrode of said glow switchand cause the initiation of a discharge in said lamp, actuating means insaid casing connected in series with saisl glow switch and having a pairof normally closed contacts for completing the circuit to said glowswitch and to said actuating means, and said contacts being operable bysaid actuating means to open the circuit to said glow "switch and saidactuating means upon the continued application of substantially the fullpotential of the source of supplyjor said discharge lamp to said glowswitch for a predetermined period of time, means normally connected in ashunt circuit with said glow switch and said actuating means andoperable upon opening of said contacts to maintain said contactslin anopen position and to prevent continued operation of said glow switch ina futile attempt to initiate a discharge in said lamp when the latterbecomes defective and said last mentioned means being automaticallyrendered inoperative with attendant closure of said contacts andrestoration of said relay device for normal operation upon replacementof the defective lamp.

7. A relay unit for starting and operating a discharge lamp comprising acasing, a glow switch disposed in said casing provided with electrodestherein one of which is a bimetallic element and between which a glowdischarge occurs upon the application of the potential of the source ofsupply for the discharge lamp, said bimetallic electrode being operableto deflect into engagement with the other electrode of said glow switchand cause the initiation of a discharge in said lamp, a low resistanceheater element in said casing connected in series with said glow switchand having a pair of normally closed contacts for completing the circuitto said glow switch and to said low resistance heater element, and saidcontacts being operable by said low resistance heater element to openthe circuit to said glow switch and said heater element upon thecontinued application of substantially the full potential of the sourceof supply for said discharge lamp to said glow switch for apredetermined period of time, a high resistance heater element normallyconnected in a shunt circuit with said glow switch and said lowresistance heater element and operable upon opening of said contacts tomaintain said contacts in an open position and to prevent continuedoperation of said glow switch in a futile attempt to initiate adischarge in said lamp when the latter becomes defective, and said highresistance heater being automatically rendered inoperative withattendant closure or said contacts and restoration of said relay devicefor normal operation upon replacement of the defective lamp.

8. A relay unit for starting and operating a discharge lamp comprising acasing, a glow switch disposed in said casing provided with electrodestherein one of which is a bimetallic element and between which a glowdischarge occurs upon the application of the potential of the source ofsupply for the discharge lamp, said bimetallic electrode being operableto deflect into engagement with the other electrode of said glow switchand caus the initiation of a discharge in said lamp, a low resistanceheater element and a bimetallic member in said casing connected inseries with said glow switch and said bimetallic element being normallyoperable to maintain closure of a pair of contacts for completing thecircuit to said glow switch and to said low resistance heater element,and said low resistance heater element being operable to heat saidbimetallic element to open the contacts and interrupt the circuit tosaid. glow switch and said heater element upon the continued applicationof substantially the full potential of the source of supply for saiddischarge lamp to said glow switch for a predetermined period of time, ahigh resistance heater element normally connected in a shunt circuitwith said glow switch and said low resistance heater element andoperable upon opening of said contacts to heat said bimetallic elementand maintain said contacts in an open position to prevent continuedoperation of said glow switch in a futile attempt to initiate adischarge in said lamp when the latter becomes detective, and said highresistance heater being automatically rendered inoperative withattendant closure of said contacts and restoration of said relay devicefor normal operation upon replacement of the defective lamp.

ROY M. SMITH. JOHN R. S'I'EEGB'I'RA.

Disclaimer 2,355,476.R0y M. Smith, Fairfield, and J 072m B. Steegstm,Bridgeport, Conn. FLUORESCENT LAMP STARTER. Patent dated Aug. 8, 1944.Disclaimer filed June H, 1951, by the assignee, The Bwyant E Zectm'oflompany.

Hereby enters this disclaimer to claims 6, 7, and 8 of said patent.

[Ofiicz'al Gazette July 10, 1951.]

Disclaimer 2,355,476.R0y M Smith, Fail-field, and J 075m B. Steegstm,Bridgeport, Conn. FLUORESCENT LAMP STARTER. Patent dated Aug. 8, 1944.Disclaimer filed June 14, 1951, by the assignee, The Bwycmt ElecmloCompany. Hereby enters this disclaimer to claims 6, 7 and 8 of saidpatent.

[Oflicz'al Gazette July 10, 1951.]

